Are you ever too old for watching cartoons?

I'm 20 years old and I still love watching cartoons like Looney Tunes, Rugrats, Batman: The Animated Series, Doug, The Simpsons, Futurama, Hey Arnold, Recess and Spongebob Squarepants. But my dad and older brother sometimes tell me I should stop watching cartoons because they think they're for kids and babies. They think I should watch TV shows like Scrubs or Lost or I ought to watch sports. But I hate watching sports because it's so boring and overrated. I intend to watch cartoons for the rest of my life.